Stereotype plate shaving machine



Aug. 11, 1936. c. s. CRAFTS 2,050,829

STEREOTYPE PLATE SHAVING MACHINE Filed MayQZl, 1954 zhgjivNToR W Patented Aug. 11 1936 UNETED S'E'AiES RATENT QFFHQE Curtis S. Crafts, Oak Park, ill, assignor to The Goss Printing Press Company, Chicago, 111., a

corporation of Illinois Application May 21, 1934, Serial No. 726,655

Claims.

The present invention relates to a stereotype plate shaving machine and more particularly to a novel and improved stereotype shaving machine for finishing the backs of stereotype plates with greater accuracy than has heretofore been possible.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, construction, arrangements, combinations and improvements herein shown and described.

The accompanying drawing, referred to herein and constituting a part hereof, illustrates one embodiment of the invention, and together with the description, serves to explain the principles of the invention.

Of the drawing:

Figure 1 is a side elevation of an illustrative embodiment of the present invention, certain parts being broken away;

Figure 2 is an end elevation of the shaving knives and their support used in connection with the mechanism shown in Figure 1;

Figure 3 is a side elevation and Figure 4 is a top plan of the part shown in Figure 2.

The present invention has for its object the provision of a stereotype plate shaving machine adapted to shave the back of stereotype plates so as to finish them with greater accuracy than has heretofore been the case. Another object is the provision of such a mechanism particularly adapted for use with curved stereotype plates such as are used on rotary newspaper presses. A further object of the invention is the provision of a stereotype plate shaving machine in which the shaving is accomplished by a plurality of knives, each of which is adapted to shave the entire back face of the plate, the knives being 50 positioned as to cut uniformly regardless of whether the other knife is still in operation or not.

In accordance with the present embodiment of the invention, which is adapted for operation on semi-cylindrical stereotype plates, a bed is provided having a concave face conforming to the true outer surface of the stereotype plate. The shaving knives are preferably mounted on a relatively heavy shaft which is coaxial with the plate and its supporting bed, and these knives are spaced a considerable distance from each other. Preferably, and as embodied, the leading knife is set on a helix or at an angle to the axis of the plate, while the trailing knife may be set either on a similar helix or parallel to the axis. By setting the leading knife on a helix, the cutting action of the leading knife is not abruptly stopped 5 at the end of the plate, but the knife gradually works off the edge of the plate and there is no violent springing of the knife shaft and machine frame such as might occur if the leading knife were parallel to the shaft axis. Furthermore, 10 sudden stopping of the cutting action of the first knife causes the second knife to be accelerated, thereby changing the depth of cut of the second or finishing knife, whereas this acceleration does not take place to vary the depth of out where the first knife is set at an acute angle with reference to its path of movement.

It will be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory of the invention but are not restrictive thereof.

Referring now in detail to the illustrative embodiment of the invention, as shown by the accompanying drawing, the stereotype plate I0, which is substantially a semi-cylinder and is to be shaved on its rear or concave face, is supported on a concave semi-cylindrical bed I! which is shaped to conform to the desired and true contour of the outer face of plate IE]. The bed H is preferably a relatively heavy casting and is supported upon a suitable standard I2, and has its upper edges connected together by means of the plates is. A suitable stop, not shown, may be provided to coact with the leading edge of the stereotype plate I0 during the shaving operation, thereby holding the plate against rotation about its axis.

The shaving knives are preferably mounted on a relatively heavy, rigid shaft I4 which is rotatably journalled in suitable bearings suppormd on plates !3 and is positioned coaxially with the plate iii and its concave bed i I. For rotating the shaft i l, and the shaving knives carried thereby, a worm gear I5 is keyed to one end of the shaft l4 and meshes with a worm I6 carried on shaft I1, and shaft ll may be driven from pulley l8 through a manual clutch l9.

As shown, the shaving knives are arranged in accordance with the present invention and comprise the leading knife 2 and a trailing knife 2! mounted on arms 22 and 23 respectively, which may be integral with each other and are also keyed to the shaft I d. The leading knife 20 is bolted to the forward and helical face of arm 22 by bolts 24, and is so formed that its outer or cutting edge is positioned to shave away the major portion of the metal which must be removed to produce the desired cylindrical surface corresponding to the proper surface for the rear face of the plate. The trailing knife 2! is preferably secured to its supporting arm 23 so that it is positioned approximately or degrees behind the inclined knife 20, and the shaving or outer edge of knife 2! is set so that the cut produced by this knife is a true cylindrical ,surface of slightly larger diameter than the surface produced by knife 20. In other words, the leading knife takes a preliminary or roughing out while the trailing knife 2| makes a smaller and finishing cut.

In the operation of the illustrative embodiment of the invention, the plate I0 is positioned on its bed II with the forward edge of the plate against the forward stop. Pulley I8 is then rotated to drive gear 15 and the knives 28 and 2|, and knife 25] removes the major portion of the surplus met-a1 from the back of the plate, being followed by knife 2! which brings the concave face of the plate to the exact size desired. As the cutting continues, the knife 20 approaches the forward edge of the plate and gradually and easily leaves this edge of the plate, thereby avoiding any sud-den release of the strain placed on the knife shaft I4. The rotation of the knives continues until after knife 2! has also passed the forward edge of the plate and the plate has been finished uniformly over its rear face.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What I claim is:

1. A stereotype plate trimming machine including in combination a cylindrical plate supporting bed, a shaft concentric therewith, a roughing cutter mounted on said shaft, said cutter having only angular cutting movement relatively to the plate on said bed and having a helical cutting edge concentric with the required finished interior of the plate, and a finishing cutter mounted on said shaft in fixed relation to said roughing cutter, the cutters being spaced to act simultaneously on a plate.

2. A stereotype plate trimming machine ineluding in combination a cylindrical plate supporting bed, a shaft concentric therewith, a roughing cutter mounted on said shaft, said outter having only angular cutting movement relatively to the plate on said bed and having a helical cutting edge concentric with the required finished interior of the plate and cutting entirely across the plate, and a finishing cutter mounted on said shaft in fixed relation to said roughing cutter, the cutters being spaced to act simultaneously on a plate.

3. A stereotype plate trimming machine including in combination a cylindrical plate supporting bed, a shaft concentric therewith, a roughing cutter mounted on said shaft, said outter having only angular cutting movement relatively to the plate on said bed and having a helical cutting edge concentric with the required finished interior of the plate, and a finishing cutter having a straight cutting edge and being mounted on said shaft in fixed relation to said roughing cutter, the cutters being spaced to act simultaneously on a plate.

4. A stereotype plate trimming machine ineluding in combination a cylindrical plate supporting bed, a shaft concentric therewith, an arm fixed to said shaft, a roughing cutter mounted on said arm, said cutter having only angular cutting movement relatively to the plate on said bed with its cutting edge in fixed relation thereto, a second arm fixed to said shaft, a finishing cutter mounted on said second arm with its cutting edge in fixed relation thereto, said cutting edges being spaced to act simultaneously on a plate and to concurrently exert a forward and outward thrust on the plate against its support bed during the joint cutting.

5. A stereotype plate trimming machine including in combination a cylindrical plate supporting bed, a rotatable roughing cutter having a helical cutting edge concentric with the required finished interior of the plate, said edge cutting the entire width of the plate at one time, said cutter having only angular cutting movement about its own axis, and a finishing cutter rotating about the same axis in fixed relation to said roughing cutter blade, the cutters being spaced to act simultaneously on the plate.

CURTIS S. CRAFTS. 

